Back to Skool: Routine at F073

F073: Restart the command list or make a teacher tell the kids to sit down

Used by the teachers' command lists 0x16, 0x18, 0x3A, 0x3C and 0x3E. Restarts the teacher's command list if it's not time to start the class yet; otherwise makes the teacher tell the kids to sit down.

Input
H	Teacher's character number (0xC9-0xCC)

F073

LD A,($7FE4)

Collect the MSB of the lesson clock (which starts at 0x10)

F076

CP $0C

Is it time to tell the kids to sit down yet?

F078

JR C,$F080

Jump if so

F07A

LD L,$1D

Otherwise signal that the command list is to be restarted

F07C

SET 0,(HL)

F07E

JR $F097

F080

CALL $627D

Collect the event indicator for the start of the lesson (0x08, 0x09, 0x0A, 0x0B or 0x0C) from the command list

F083

LD C,A

Save the event indicator in C briefly

F084

CALL $7C8F

Has the lesson already started?

F087

JR NZ,$F097

Jump if so (the teacher must have just returned to the classroom doorway after hunting down the truant ERIC)

F089

LD A,C

Restore the event indicator to A, and signal that the lesson has started

F08A

CALL $7C98

F08D

LD A,H

A=teacher's character number

F08E

SUB $6D

E=0x5C, 0x5D, 0x5E or 0x5F (appropriate SIT DOWN message for this teacher)

F090

LD E,A

F091

LD BC,$6A08

Redirect control to the routine at 6A08 (make character speak) and then return to F097 (below)

F094

CALL $639F

F097

JP $638C

Move to the next command in the command list